Boring tool



Sept. 27, 1949. J. F. JAwolRowsKl Erm. 2,483,096

BORING TOOL Filed 'Sept 16, 1946 A T TOR/Vf.' YS

JOSEPH. F. JAwofeoM/s/f/ Patented Sept. 27, 1949 'l f BORING TOOL Joseph F. Jaworowski,f0leveland, and Norbert J aworowski, Lakewood, Ohio Applicationseptemter 16, 1946, serial No. 697,284

This invention relates to particularly to an adjustable boring tool holder especially adapted for machining operations which involve boring holes by means of a cutting tool which is rotated relative to the work, orvice versa, to take a cut from the inside of the hole being bored.

In machine shop practice it frequently occurs that a hole must benished accurately Ato an exact size. YOne way of accomplishing this is to drill the hole smaller than nished size and then ream to the desired dimension. It may occur however that areamer of the desired size is not 'available in'which case the hole maybe finished to size by boring. With the usual, nonadjustable, boring tool the work is rotated while the tool is fed through the hole to take offv a cut.

This requires a tool support which maybe ad-V justed transversely of the hole and is not practical or convenient with large parts or those which are difficult to mount. Also many small shops do not have boring machines of the type required to do this kind of work. f 1 g It is an object of our invention'to provide an improved adjustable tool holder, particularly suited for boring applications, which may be mounted in the rotating spindle of a milling machine or drill press, or in a lathe tail stock or screw machine. Other objects? of our invention include: the provision of a tool holder 'which-may be adjusted to bore holes varyingl inl diameterthrough a substantial range; theeprovision of ani adjustable boring tool for use in various types of machine tools which may quickly beadjusted. to bore different diameter holes and which, when in adjusted position is rigidly locked in such a manner that vibration and chattering of the'tool.

is prevented, and; the provision of an inexpensive, simple, easily adjusted, and rugged tool holder of the type described which may be ac-v curately set to bore a hole of any desired size within a given range.

The above and other objects of our'inventionv will appear from the following description of; a

preferred form thereof, reference being had tov the accompanying drawings infwhich:

Figure 1 is a sideelevationof our toolholder with a boring tool mounted therein.

Figure 2 is an end elevation looking at the top of the tool holder and taken substantially online cross-sectional view posi-` 5 6 claims. (o1. 279-5) tool holders and-more' V Figure 4 is a Vertical cross-sectional view, generally similar to Figure 3 but taken at.90 to Figure 3 on line 4--4 of Figure 2.

Figure 5 is a transverse cross-sectional view taken on line 5 5 of Figure 1.

As illustrated in the drawings, our toolholder comprises a yoke member Y having a shank portion I at its upper or outer end and a pair of spaced leg portions 2 and 3 at its opposite end. The shank I may be secured in the spindle of a vertical or horizontal milling machine, drill press, or other machine tool by any suitable means. As is best seen in Figure 5, the legs 2 and 3 have parallel inner surfaces 2' and 3 and cylindrical outer surfaces 2'( and 3". Pivotally supported on a pin 4, which extends into suitable holes in the legs 2 and 3, is the tool holder bar 5. The width of the bar 5 is substantially the same as the gap between the legs 2 and 3, a sliding nt being maintained therebetween so that the bar 5 may be adjusted as will later appear.

. Surrounding the lower portion of the yoke Y is a sleeve S having a bore 6 within which the legs 2 and 3 t. The surfaces 2" and 3" of the legs 2 and 3 engage the surface of bore 6 but the pin 4 is preferably shorter than the diameter of bore 6 to avoid engagement therebetween and facilitate assembly.V vIn order to Vsecure the vsleeve S in position on the vyoke Y and present relative axial movement between these parts a retaining screw 'I is provided which has threaded engagement in a suitable. hole in the yoke`Y but has a sliding fit in a corresponding hole in the sleevejS. lThus, as is best seen in Figure 3, although the sleeve S cannot move longitudinally on the yoke Y, movement of the yoke Y and particularly the legs 2 and 3 thereof in a direction transverse to the axis of the pin 4 is not restricted. j

In orderrto vary the'angular position of the tool holder barv 5 and tool I2 relative to the extended axis 8 of the shankl, a pair of adjusting screws 9 and I Il are provided which have threaded engagement in suitable holes extending through the wall of the sleeve S on opposite sides of the pin 4. The axes of screws 9 and I0 extend transversely of and substantially normal to the axis receive the shank of a tool I2 and the set screw I3 is adapted to clamp the tool in position. One

side of the shank of the tool I2 may be slightlyv flattened as seeniin Figure 3 toform a seat for 3 the end of the set screw I3 and prevent rotation of the tool l2 in the holder bar 5.

In Figures 1, 2, and 3 the bar 5 and tool l2 are shown in their maximum angular position relative to the center line 8 of the shank I. It will be understood that when in this position the apparatus will be set to bore a hole of maximum diameter. If it is desired to adjust the bar 5 and tool l2 to bore a smaller hole, or take a lighter cut, the screw l will be loosened or withdrawn and the screw 9 tightened or screwed inwardly through the sleeve S. In order to iacili. tate adjustment of the position of the bar a spring pressed plunger l has a sliding t in a hole I5 in the har 5 and is urged outwardly by a compression spring I6. The plunger i4 always tends to urge the bar 5 in a counter-Clockwise direction as seen in Figure 3. As the set screw lll is withdrawn the plunger 14 will cause the Y holder bar 5 to remain in Contact with the end o1" the set screw lo, thus facilitating setting and adiustnient of the tool.

As noted above, after the set screw l0 is.. positioned to place the holder bar 5. in the desired angular relation to the center line 3 of the shank l, the set Screw S is tightened against the upper end oi the bar 5. Thos the screws 9 and It will bold the bar 5 iiimly against the pin 4. eliminatins any oley or lost motion which may be present between the pin t and. the ber 5.. Furthermore, when the screws 9 and lll are tightened against the bar 5 they will act through the pin li to urge the les portions 2 and 3 of the yoke. Y toward the opposite side o f the sleeve S, lAs this pressure is applied to the legsl 2 and` 3 they are wedged together due to the inwardly tapering form oi. their outer surfaces and the corresponding form of thev bore E in the sleeve 8. 'Ihis wedging action will cause the inner surfaces 2' and 3' of the legs Z and 3 to grip the outer surfaces of the bar 5,. thus providing an additional lock against movement of ber 5 relative to the other parte and making en. exceedingly rigid end completely chatter-proof tool holder unit. rI his clamping or wedging action on the legs 2 and 3 is facilitated by slightly relieving the yokeV Y at |71 so that only the leg portions of the yoke Y are in contact with the inner bore 6 of the sleeve S.`

It will be seen from the above description that our boring to'ol holder may readily and accurately be adjusted through a substantial range to vary the position of the cutting tool l2V relative to the center line of the tool holder shank l. It will be understood that the degree of possible adjustment may be increased or decreased by" varying the proportion of the parts of our tool holder assembly. Our device may, of course, be made in various sizes and with either1 a straight or tapered shank portion l and the means for securing a cutting tool in the holder bar 5 may be varied as desired. It will further'be understood that although we have illustrated the adjusting screws 9 and I!) as adapted both to lock the holder bar` 5against pivotal movement about the pin 4 and to exert the wedging force which takes up any play orlooseness between the yoke Y and sleeve S and causes the legs 2 and 3 to grip the bar 5, in some cases it might be desirable to provide supplementary means to` exert a force between the sleeve S and the spaced apart legs of the yoke Y to cause the wedging action to` occur. Y

Therefore, although we have described the illustrated embodimentof our invention in considerable detail it will be understood by those skilled in the art that variations and modications may be made in the form, arrangement, and proportions of the parts and we, therefore, do not wish to be limited to the particular device herein illustrated and described but claim as our invention all forms thereof coming within the scope of the appended claims.

We claim:

l. In a tool holder of the type'described a yoke member havinga shank portion at one end, a tool holder bar pivotally supported in said yoke, a sleeve disposed around said yoke member, means for securing said yoke against axial move.- ment in said sleeve, and adjustable means for locking said bar against movement relative to said yoke and sleeve.

.2. A tool holder comprising a sleeve having a cylindrical bore extending therethrough, a yoke member having spaced legs disposed within said bore and a shank portion extending in the opposite direction fromsaid legs., means for securing said legs oi said yoke against axial movement in said bore of said sleeve, a pin extending between the legs of said yoke, a tool holder bar supported on .Said pin for Vlimited movement about the axis thereof, tool holding means at one end of said bar, and adjustable means for engaging said bar and VadjustaJoly securing same against movement about the axis of said pin.

3. In a tool holder of the type described, a yoke member having a shank portion at one end and spaced legs at the other end, the outer surfaces of said legs. being generally cylindrical, a sleeve having a cylindrical bore adapted to t over said spaced legs, means for securing said sleeve to said yoke with the spaced legs of the yoke disposed in the bore of the sleeve, said securing means being adapted to restrain axial movement while permitting limited transverse movement of said yoke in said bore, a tool holder bar pivotally supported between the, legs of said yoke for limited oscillating movement, adjustable means for securing said barV against pivotal movement relative to said yoke, said adjustable securing means. also being adapted to urge said yoke legs transversely of said bore whereby said legs will be wedged together by said sleeve and caused to grip said bar, and tool holding means at the outer end of said bar.

4. In a. tool holder of the type described, a slotted yoke having spaced legs, said legs having parallel inner surfaces, a pin extending transversely across between said legs, a tool holder bar pivotally supported on said pin between said legs, the thickness of said bar being substantially equal to the distance between said parallel surfaces of said spaced legs, a sleeve member secured to said yoke and surrounding the legs thereof, means for preventing relative axial movement between said yoke and said sleeve, and adjusting vscrews extending through and having threaded engagement with said sleeve and engaging the lsame side of said bar but on opposite sides of said -pin whereby when Vsaid screws Aare tightened against said bar pivotal movement of said .bar will be prevented, the axes of said screws being substantially parallel to said inner surfaces of' said'legs. l

5. In a tool holder of the type describeda slotted yoke having spaced legs, said legs having parallel inner surfaces, a pin extending transversely across between: said legs, a tooll holder bar pivotally supported on said pin between said legs, the thickness of said baribeing substantially equal to the distance between said parallel sur-` faces of said spaced legs, a sleeve member secured to said yoke and surrounding the legs thereof, adjusting screws extending through and having threaded engagement with said sleeve and engaging the same side of said bar but on opposite sides of said pin whereby when said screws are tightened against said bar pivotal movement of said bar will be prevented, the axes of said screws being substantially parallel to said inner surfaces of said legs, and spring means tending to rotate said bar in one direction about said pivotal support and to hold said bar in engagement with one of said adjusting screws.

6. A tool holder comprising a yoke member having spaced leg portions, a tool holder bar pivotally supported in said yoke between said spaced leg portions, a sleeve disposed around said yoke member, means for securing said yoke member against axial movement in said sleeve while permitting transverse movement thereof in said sleeve, and means for urging said yoke REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 524,375 Blue Aug. 14, 1894 1,980,178 Berglund Nov. 13, 1934 2,369,875 Wanelik Feb. 20, 1945 FOREIGN PATENTS Number Country Date 93,037 Switzerland Dec. 9, 1920 

